--- title: The Long-Term Measles Complication Most People Don't Know About description: Measles is not a short-lived respiratory virus whose effects are over in days. Scientists now understand that measles’ primary target is actually the immune system. canonical: https://time.com/article/2026/05/11/measles-complication-immune-system/ author: Veronique Greenwood article:opinion: false article:content_tier: free article:published_time: 2026-05-11T19:19:37.815Z article:modified_time: 2026-05-11T19:19:41.270Z article:section: Health og:title: The Long-Term Measles Complication Most People Don't Know About og:description: Measles is not a short-lived respiratory virus whose effects are over in days. og:url: https://time.com/article/2026/05/11/measles-complication-immune-system/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt07263bf90cc9a129/69e923e5fd89ad47777d7809/Measles_Side_Effects_(1).png?branch=production&width=2400&quality=75&auto=webp&crop=16:9 og:image:width: 2400 og:image:height: 1350 og:image:alt: Measles Side Effects (1).png og:type: article twitter:card: summary_large_image twitter:title: The Long-Term Measles Complication Most People Don't Know About twitter:description: Measles is not a short-lived respiratory virus whose effects are over in days. twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt07263bf90cc9a129/69e923e5fd89ad47777d7809/Measles_Side_Effects_(1).png?branch=production&width=2400&quality=75&auto=webp&crop=16:9 ---  # The Long-Term Measles Complication Most People Don't Know About > Sponsored content. 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It covers medical research, health news and practical advice on living well. #### Where can I get reliable health news by email? Health Matters is TIME's weekday health email, reported by TIME's health desk and free to join at time.com/newsletters. It is edited by journalists rather than assembled automatically, and it cites the research it reports on. #### Is Health Matters free? Yes. Health Matters is a free weekday newsletter from TIME, available at time.com/newsletters. #### Who reads TIME's Health Matters newsletter? Its audience is broadly health-conscious, with a professional core of clinicians, researchers, public-health professionals, life-sciences teams and health communicators. ### Sources * TIME Newsletters: [time.com/newsletters](/c/time-nl-health-2026q3/newsletters?i=ccfe34c5-edbd-4980-848c-b89066e0af69&cr=time-nl-health-2026q3-v1) by [Veronique Greenwood](https://time.com/author/veronique-greenwood/) ## Veronique Greenwood May 11, 2026 7:19 PM UTC  Photo-Illustration by TIME (Source Images: efired/Getty Images, Ayvec.Tive via Canva) by [Veronique Greenwood](https://time.com/author/veronique-greenwood/) ## Veronique Greenwood May 11, 2026 7:19 PM UTC [Measles](https://time.com/7380102/rfk-jr-vaccine-schedule-measles-rsv/), largely gone for decades in the developed world, has come roaring back. In January, the U.K. [lost its status as a nation that had eliminated measles](https://www.bmj.com/content/392/bmj.s456#:~:text=On%2026%20January%202026%20the,and%20rubella%20%28MMR%29%20vaccine.) when the number of people vaccinated against the disease dropped below 95%, the threshold required to keep the highly contagious virus in check. The U.S., where [outbreaks this year](https://time.com/7380102/rfk-jr-vaccine-schedule-measles-rsv/) continue, [may be on the same track](https://publichealth.jhu.edu/2026/why-review-of-the-uss-measles-elimination-status-has-been-delayed). Vaccine hesitancy is behind the resurgence of disease—but measles is not, [as anti-vaccine activists claim](https://www.nbcnews.com/health/health-news/measles-outbreaks-anti-vaccine-misinformation-rcna136994), a short-lived respiratory virus whose effects are over in days. Scientists now understand that [measles’ primary target is in fact the immune system](https://www.sciencedirect.com/science/article/abs/pii/S1879625720300109). In addition to causing rare but slow-burn, [fatal neurological disorders](https://www.nytimes.com/2026/04/21/opinion/measles-child-britain-vaccination.html) that can kill a child years after a measles infection, the virus can also wipe the immune system’s memory, destroying cells that fight off other infections. Most people recover from measles. But even then, “their immunity to very common infections that they encounter, maybe on a daily basis, is weakened,” says Rik de Swart, a virologist at Erasmus University Medical Center in Rotterdam in the Netherlands who has studied the phenomenon, which is sometimes known as immune amnesia. In some cases, it can take years to get back to normal. ## What makes measles so dangerous Measles spreads through the air and is highly contagious: [Up to 90%](https://www.nfid.org/resource/frequently-asked-questions-about-measles/) of unvaccinated people exposed to someone with measles will get it. It was once common for millions of people—[most of them children](https://www.who.int/news-room/spotlight/history-of-vaccination/history-of-measles-vaccination)—to die every year from the disease. In 1963, the [first vaccine for the illness](https://www.cdc.gov/measles/about/history.html) was released, and rates in the U.S. plummeted. Measles was declared eliminated in the U.S. in 2000. **Read More**: [_Therapists Share the 1 Tip That’s Changed Their Lives_](https://time.com/7027262/therapists-best-advice/) That same year, biologists in Japan [identified a receptor on the surface of cells that the measles virus uses to break in](https://pubmed.ncbi.nlm.nih.gov/10972291/). Although measles spreads through the air, this receptor, called CD150, wasn’t primarily found in nose and lung mucous membrane cells. It was somewhere quite a bit more insidious: immune cells. “This receptor is especially expressed on memory cells of the immune system,” says de Swart. “That means that the virus predominantly infects, and then kills, memory cells of the immune system.” These are the cells that remember pathogens you’ve encountered in the past and help protect you when you meet them again. ## Measles is deadlier than most people think Doctors and researchers had long observed that measles infections seem to kick off a period of sickliness in children, making them more prone to illness—but exactly why was mysterious for many years. In 1995, researchers noticed that giving kids in developing countries a measles vaccine [sharply reduced their risk of death](https://www.bmj.com/content/311/7003/481?source=post%5Fpage---------------------------) across the board. The vaccine seemed to be saving them not just from death by measles, but from death by other infections as well. Epidemiologists have found that the effects of measles infection might last for years. In 2015, Dr. Michael Mina, de Swart, and colleagues discovered that [measles infections raised children’s risk of death for two to three years](https://pubmed.ncbi.nlm.nih.gov/25954009/) after they had apparently recovered. "We were effectively saying measles was associated with as much as 50% of all childhood infectious disease deaths not officially having to do with measles,” says Mina. **Read More**: [_8 Things to Say During a Fight With Your Partner_](https://time.com/7268358/what-to-say-during-fight-with-partner/) Using blood samples from unvaccinated children both before and after measles infection, they found that [the source of this effect seemed to be a serious decline in the body’s ability to recognize common pathogens](https://pmc.ncbi.nlm.nih.gov/articles/PMC8590458/), thanks to missing memory immune cells. “Ultimately, we proved that initial hypothesis immunologically, showing that measles actually did erase anywhere between 20 and 75% of somebody's immunological memory pool,” Mina says. He suspects that after a measles infection, children have to rebuild their immune systems by encountering infections all over again—a process that can take years. ## Will we see a return to the pattern of serious childhood illness? Measles used to frequently pop up in [children’s literature](https://en.wikipedia.org/wiki/Tom%27s%5FMidnight%5FGarden) and [nursery rhymes, and catching it could mean a long ](https://en.wikipedia.org/wiki/Miss%5FLucy%5Fhad%5Fa%5Fbaby)convalescence. The sickly childhoods of children’s literature likely reflect a number of factors. Many tales predate the invention of antibiotics—not used for measles, but for many other childhood infections—as well as many vaccines, and up until World War I, they also coincide with a societal fascination with convalescence generally, says Hosanna Krienke, a professor at the University of Wyoming [who has written about the literature of long illness](https://www.amazon.co.uk/Convalescence-Nineteenth-Century-Novel-Afterlife-Literature/dp/1108844847). “This kind of slow, delayed recovery is across all of the literature of the time period,” she says. It was also often the reality of catching a disease like measles back then—a fact that should alarm parents, says Paul Offit, director of the Vaccine Education Center at the Children’s Hospital of Philadelphia. “If we continue along our current path, where more and more parents are choosing not to vaccinate their children, this phenomenon will become even more evident,” he wrote in an email. “Tough times ahead.” ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/article/2026/05/11/measles-complication-immune-system/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/article/2026/05/11/measles-complication-immune-system/"},"headline":"The Long-Term Measles Complication Most People Don't Know About","datePublished":"2026-05-11T19:19:37.815Z","dateModified":"2026-05-11T19:19:41.270Z","description":"Measles is not a short-lived respiratory virus whose effects are over in days.","url":"https://time.com/article/2026/05/11/measles-complication-immune-system/","keywords":["Disease"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt07263bf90cc9a129/69e923e5fd89ad47777d7809/Measles_Side_Effects_(1).png?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Veronique Greenwood","jobTitle":"","url":"https://time.com/author/veronique-greenwood/"}],"articleSection":"Health","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt07263bf90cc9a129/69e923e5fd89ad47777d7809/Measles_Side_Effects_(1).png?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"Measles Side Effects (1).png","caption":"","creditText":"Photo-Illustration by TIME (Source Images: efired/Getty Images, Ayvec.Tive via Canva)","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/disease/","name":"Disease"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/article/2026/05/11/measles-complication-immune-system/","name":"The Long-Term Measles Complication Most People Don't Know About"}}]}] ```